Packard Bell No visual input

I have a Packard Bell IXTREME 6003 and have recently installed a ATI Radeon 9550 Graphics Card as the onboard graphics would not allow new games to play. Installation was successfull but when i went to play a game, the monitor went off and a message saying "No visual input" came up followed by "Power Saving" and there was no way of getting out of it. I then updated the cards drivers and uppdated the motherboard drivers and still i have the same problem. I can get as far as a games loading screen and on one game i actually played for 20 seconds until it happened. Thing is, it wont let me play any games now, even ones that i used to be able to play.

I have seen a 500W Power Supply and a 256MB RAM together for £40. Should i choose to take this option? I just dont want to pay money and still have a problem at the end of it. I also updated the BIOS with the download off the Packard Bell Web Site and still no hope, only went a little bit further in the game.

I would say it's a waste of money but that is only my view,my first computer was a HP Brio that computer is still going well as i upgraded as far as i could,but know you can't play games on it,it all depends on how large your wallet is.Another way of looking at it is you can't put a formula 1 engine into a mini as with older computers.